v.net.connectivity.1grass man page

v.net.connectivity — Computes vertex connectivity between two sets of nodes in the network.

Keywords

vector, network, connectivity

Synopsis

v.net.connectivity
v.net.connectivity --help
v.net.connectivity input=name [arc_layer=string] [node_layer=string] [arc_column=name] [arc_backward_column=name] output=name [node_column=name] [set1_cats=range] [set1_where=sql_query] [set2_cats=range] [set2_where=sql_query] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags

--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--ui
Force launching GUI dialog

Parameters

input=name [required]
Name of input vector map
Or data source for direct OGR access
arc_layer=string
Arc layer
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
Default: 1
node_layer=string
Node layer
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
Default: 2
arc_column=name
Arc forward/both direction(s) cost column (number)
arc_backward_column=name
Arc backward direction cost column (number)
output=name [required]
Name for output vector map
node_column=name
Node cost column (number)
set1_cats=range
Set1 category values
Example: 1,3,7-9,13
set1_where=sql_query
Set1 WHERE conditions of SQL statement without ’where’ keyword
Example: income < 1000 and inhab >= 10000
set2_cats=range
Category values
Set2 category values
set2_where=sql_query
Set2 WHERE conditions of SQL statement without ’where’ keyword
Example: income < 1000 and inhab >= 10000

Description

v.net.connectivity computes vertex connectivity between two sets, i.e. the minimum number of vertices whose removal would separate two given sets.

Notes

Two sets (set1 and set2) are specified by respective layer, where and cats parameters. Similarly to v.net.flow module, capacities of nodes can be given by node_column option. v.net.connectivity finds the set of nodes of minimum total capacitiy separating the two given sets and outputs map containing points on the positions of these nodes. Default capacity, which is used when no column is specified, is one.

Examples

The following command finds the minimum number of intersections separating roads on the left bank from roads on the right bank.

v.net.connectivity input=roads output=roads_conn set1_where="bank=left" \
      set2_where="bank=right"
v.net.connectivity input=airtraffic output=connectivity \
      set1_where="name=JFK" set2_where="name=Heathrow" node_column=capacity

See Also

v.net, v.net.flow, v.net.bridge

Authors

Daniel Bundala, Google Summer of Code 2009, Student
Wolf Bergenheim, Mentor

Last changed: $Date: 2014-12-24 15:44:33 +0100 (Wed, 24 Dec 2014) $

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